'Tanne West' was a German unrealised plan for the capture from the Finns of the Åland islands group, off the south-western corner of Finland in the mouth of the Gulf of Bothnia, in the event of a Finnish surrender to the Soviets (August/3 September 1944).

Adolf Hitler was concerned about the operation’s viability right from the start, for he was acutely conscious of the fact that Sweden, with which he wished wished to maintain friendly relations, had its own eyes of the Åland islands group, and was then on 3 September was informed that the infantry division earmarked as the core of the invasion force would have to be retained in Denmark, and that the navy could spare no troops as they were needed for 'Tanne Ost'. Hitler immediately cancelled the undertaking despite the fact that the heavy cruiser (ex-pocket battleship) Lützow and destroyers Z 25, Z 28, Z 35 and Z 36 had already anchored just outside Swedish territorial waters, in the area of Utö island off Stockholm, to be on hand for transport and to provide gunfire support.